Re: [PATCH v2 1/6] MdeModulePkg/MdeModulePkg.dec: Add NULL pointer detection PCD

["Wang, Jian J" <jian.j.wang@intel.com>]

Sure. Thanks for the feedback.

> -----Original Message-----
> From: Zeng, Star
> Sent: Monday, September 25, 2017 4:01 PM
> To: Wang, Jian J <jian.j.wang@intel.com>; edk2-devel@lists.01.org
> Cc: Dong, Eric <eric.dong@intel.com>; Laszlo Ersek <lersek@redhat.com>; Yao,
> Jiewen <jiewen.yao@intel.com>; Kinney, Michael D
> <michael.d.kinney@intel.com>; Justen, Jordan L <jordan.l.justen@intel.com>;
> Wolman, Ayellet <ayellet.wolman@intel.com>; Zeng, Star
> <star.zeng@intel.com>; Gao, Liming <liming.gao@intel.com>
> Subject: RE: [PATCH v2 1/6] MdeModulePkg/MdeModulePkg.dec: Add NULL
> pointer detection PCD
> 
> You may need also add PcdNullPointerDetectionPropertyMask prompt and help
> into the MdeModulePkg.uni.
> 
> 
> Thanks,
> Star
> -----Original Message-----
> From: Wang, Jian J
> Sent: Thursday, September 21, 2017 1:20 PM
> To: edk2-devel@lists.01.org
> Cc: Wang, Jian J <jian.j.wang@intel.com>; Zeng, Star <star.zeng@intel.com>;
> Dong, Eric <eric.dong@intel.com>; Laszlo Ersek <lersek@redhat.com>; Yao,
> Jiewen <jiewen.yao@intel.com>; Kinney, Michael D
> <michael.d.kinney@intel.com>; Justen, Jordan L <jordan.l.justen@intel.com>;
> Wolman, Ayellet <ayellet.wolman@intel.com>
> Subject: [PATCH v2 1/6] MdeModulePkg/MdeModulePkg.dec: Add NULL pointer
> detection PCD
> 
> From: "Wang, Jian J" <jian.j.wang@intel.com>
> 
> PCD PcdNullPointerDetectionPropertyMask is a bitmask used to control the
> NULL address detection functionality in code for different phases.
> 
> If enabled, accessing NULL address in UEFI or SMM code can be caught as a
> page fault exception.
> 
>     BIT0    - Enable NULL pointer detection for UEFI.
>     BIT1    - Enable NULL pointer detection for SMM.
>     BIT2..6 - Reserved for future uses.
>     BIT7    - Disable NULL pointer detection just after EndOfDxe. This is a
>               workaround for those unsolvable NULL access issues in
>               OptionROM, boot loader, etc. It can also help to avoid
>               unnecessary exception caused by legacy memory (0-4095) access
>               after EndOfDxe, such as Windows 7 boot on Qemu.
> 
> Cc: Star Zeng <star.zeng@intel.com>
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Michael Kinney <michael.d.kinney@intel.com>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Ayellet Wolman <ayellet.wolman@intel.com>
> Suggested-by: Ayellet Wolman <ayellet.wolman@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
> ---
>  MdeModulePkg/MdeModulePkg.dec | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/MdeModulePkg/MdeModulePkg.dec
> b/MdeModulePkg/MdeModulePkg.dec index 403a66a5ad..3f90b8d7e6 100644
> --- a/MdeModulePkg/MdeModulePkg.dec
> +++ b/MdeModulePkg/MdeModulePkg.dec
> @@ -863,6 +863,19 @@
>    # @ValidList  0x80000006 | 0x03058002
> 
> gEfiMdeModulePkgTokenSpaceGuid.PcdErrorCodeSetVariable|0x03058002|UIN
> T32|0x30001040
> 
> +  ## Mask to control the NULL address detection in code for different phases.
> +  #  If enabled, accessing NULL address in UEFI or SMM code can be
> caught.<BR><BR>
> +  #    BIT0    - Enable NULL pointer detection for UEFI.<BR>
> +  #    BIT1    - Enable NULL pointer detection for SMM.<BR>
> +  #    BIT2..6 - Reserved for future uses.<BR>
> +  #    BIT7    - Disable NULL pointer detection just after EndOfDxe. <BR>
> +  #              This is a workaround for those unsolvable NULL access issues in
> +  #              OptionROM, boot loader, etc. It can also help to avoid unnecessary
> +  #              exception caused by legacy memory (0-4095) access after EndOfDxe,
> +  #              such as Windows 7 boot on Qemu.<BR>
> +  # @Prompt Enable NULL address detection.
> +
> +
> gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask|0x0
> + |UINT8|0x30001050
> +
>  [PcdsFixedAtBuild, PcdsPatchableInModule]
>    ## Dynamic type PCD can be registered callback function for Pcd setting action.
>    #  PcdMaxPeiPcdCallBackNumberPerPcdEntry indicates the maximum number
> of callback function
> --
> 2.14.1.windows.1